In recent years, with the development of the wireless communication technology, on one hand, a mobile phone device is provided with more and more functions, from the call and short message functions at the very beginning to the later terminal application components like Bluetooth, Global Positioning System (GPS) navigation, wireless local area network, mobile TV and Near Field Communication (NFC), more and more functions are integrated on the mobile phone device; on the other hand, from a user experience perspective, people hope that the mobile phone device can be made small, light and thin, and convenient to carry. Both of the two aspects make it increasingly difficult to design the mobile phone device; certainly, with the improvement of various chip manufacture techniques, the chip can be encapsulated smaller and smaller, which makes it possible to implement more and more functions on the same PCB board, but the space required by an antenna which serves as an air outlet for implementing these terminal application components cannot be reduced.
The current smart phone generally supports multiband network, Bluetooth, GPS, WIFI and other functions, then a multiband main antenna, a Bluetooth antenna, a GPS antenna, a WIFI antenna and other antennae are needed for implementing these functions together; to design and implement these antennae on the mobile phone at the same time, the design faces a great challenge. For achieving the excellent radiation performance, the antenna is usually set at edge or corner of the mobile phone device, and occupies a certain PCB space; generally, the more the space occupied by the antenna is, the better the radiation performance is. However, because there are too many antennae on the mobile phone device, the space allocated to each antenna is limited, and then the antenna performance cannot be optimized, which influences the user experience.